Ganguli Mary, Snitz Beth E, Saxton Judith A, Chang Chung-Chou H, Lee Ching-Wen, Vander Bilt Joni, Hughes Tiffany F, Loewenstein David A, Unverzagt Frederick W, Petersen Ronald C
Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA.
Arch Neurol. 2011 Jun;68(6):761-7. doi: 10.1001/archneurol.2011.101.
Mild cognitive impairment (MCI) has been defined in several ways.
To determine the 1-year outcomes of MCI by different definitions at the population level.
Inception cohort with 1-year follow-up. Participants were classified as having MCI using the following definitions operationalized for this study: amnestic MCI by Mayo criteria, expanded MCI by International Working Group criteria, Clinical Dementia Rating (CDR) = 0.5, and a purely cognitive classification into amnestic and nonamnestic MCI.
General community.
Stratified random population-based sample of 1982 individuals 65 years and older.
For each MCI definition, there were 3 possible outcomes: worsening (progression to dementia [CDR ≥ 1] or severe cognitive impairment), improvement (reversion to CDR = 0 or normal cognition), and stability (unchanged CDR or cognitive status).
Regardless of MCI definition, over 1 year, a small proportion of participants progressed to CDR > 1 (range, 0%-3%) or severe cognitive impairment (0%-20%) at rates higher than their cognitively normal peers. Somewhat larger proportions of participants improved or reverted to normal (6%-53%). Most participants remained stable (29%-92%). Where definitions focused on memory impairment and on multiple cognitive domains, higher proportions progressed and lower proportions reverted on the CDR.
As ascertained by several operational definitions, MCI is a heterogeneous entity at the population level but progresses to dementia at rates higher than in normal elderly individuals. Proportions of participants progressing to dementia are lower and proportions reverting to normal are higher than in clinical populations. Memory impairments and impairments in multiple domains lead to greater progression and lesser improvement. Research criteria may benefit from validation at the community level before incorporation into clinical practice.
轻度认知障碍（MCI）有多种定义方式。
在人群层面确定不同定义的MCI的1年转归情况。
起始队列，随访1年。采用为本研究实施的以下定义将参与者分类为患有MCI：根据梅奥标准的遗忘型MCI、根据国际工作组标准的扩展型MCI、临床痴呆评定量表（CDR）=0.5，以及分为遗忘型和非遗忘型MCI的单纯认知分类。
普通社区。
基于人群的1982名65岁及以上个体的分层随机样本。
对于每种MCI定义，有3种可能的转归：病情恶化（进展为痴呆[CDR≥1]或严重认知障碍）、改善（恢复到CDR = 0或正常认知）和稳定（CDR或认知状态不变）。
无论MCI的定义如何，在1年期间，一小部分参与者进展为CDR>1（范围为0%-3%）或严重认知障碍（0%-20%），其发生率高于认知正常的同龄人。有较大比例的参与者改善或恢复到正常（6%-53%）。大多数参与者保持稳定（29%-92%）。在聚焦于记忆损害和多个认知领域的定义中，按CDR衡量，病情进展的比例较高，恢复的比例较低。
通过几种操作性定义确定，MCI在人群层面是一个异质性实体，但进展为痴呆的发生率高于正常老年人。进展为痴呆的参与者比例低于临床人群，恢复到正常的比例高于临床人群。记忆损害和多领域损害导致更大的病情进展和更小的改善。在纳入临床实践之前，研究标准可能受益于社区层面的验证。
